A density functional theory study of the hydrolysis mechanism of phosphodiester catalyzed by a mononuclear Zn(II) complex
A density functional theory study of the hydrolysis mechanism of phosphodiester catalyzed by a mononuclear Zn(II) complex
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单核Zn(II)配合物催化磷酸二酯水解机理的密度泛函理论研究
DOI：
10.1016/j.molcata.2012.11.025
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发表时间：
2013-03
期刊：
影响因子：
--
通讯作者：
Zhao, Cunyuan
中科院分区：
文献类型：
--
作者：
Xu, Huiying;Xu, Jianqiao;Chao, Hui;Zhao, Cunyuan
采用密度泛函理论（DFT）计算探讨了1,5,9-三氮杂环十二烷（Zn:([12] aneN3)）单核锌（II）：OH -配合物催化的DNA类似物BNPP （BNPP=二（4-硝基苯基）磷酸）的水解机理。我们提出了一种结合模式，其中一个末端磷酰氧原子以及亲核基团（羟基阴离子）与锌中心结合。发现两种可能的反应机制：一种是协同反应机制，隐式溶剂液相的反应势垒为18.1kcal/mol，水分子显式溶剂液相的反应势垒为13.8kcal/mol；另一种是具有准三角双金字塔结构的羟基化磷酸盐反应中间体的逐步机制，但不太可行。协同反应途径和分步反应途径均为SN2型亲核取代反应。同时，极性质子溶剂如水、甲醇和乙醇在催化水解机制中更受青睐。我们探索了单阴离子磷酸盐在瞬态产物中去质子化的合理性，发现质子很难解离，最终产物是NPP -而不是NPP2 -。这些结果与实验结果一致，系统地解释了实验结果，更重要的是为催化剂的设计和溶剂的选择提供了有益的建议。
Density functional theory (DFT) calculations were used to explore the hydrolysis mechanism of the DNA analog BNPP (BNPP=bis(4-nitrophenyl)phosphate) catalyzed by the mononuclear zinc(II):OH−complex of 1,5,9-triazacyclododecane (Zn:([12] aneN3)). We present a binding mode in which one terminal phosphoryl oxygen atom as well as the nucleophilic group (hydroxyl anion) binds to zinc center. Two potential mechanisms were found as follows: one is a concerted mechanism with a reaction barrier of 18.1kcal/mol in liquid phase of implicit solvent and 13.8kcal/mol in liquid phase of explicit solvent of water molecules; the other is a stepwise mechanism with a hydroxylated phosphate reaction intermediate of a quasi-trigonal bipyramid configuration but is less feasible. Both the concerted reaction pathway and stepwise reaction pathway are SN2 manner of nucleophilic substitution reactions. Meanwhile polar protic solvents like water, methanol and ethanol are favored in the catalyst-assisted hydrolysis mechanism. We explore the rationality of deprotonation of mono-anionic phosphates in the transient products and find that it is difficult to dissociate a proton and the ultimate product is NPP−rather than NPP2−. These results are consistent with and systematically interpret the experimental observations, more importantly, provide useful suggestions in the catalyst design and solvent selection.
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DOI：
10.1002/chin.200644271
发表时间：
2006-10
期刊：
ChemInform
影响因子：
--
作者：
W. Cleland;A. Hengge
通讯作者：
W. Cleland;A. Hengge
影响因子：
--
作者：
GONZALEZ, C;SCHLEGEL, HB
通讯作者：
SCHLEGEL, HB
影响因子：
15
作者：
E. Kövári;R. Krämer
通讯作者：
E. Kövári;R. Krämer
影响因子：
4.6
作者：
Mohamed, Mark F.;Neverov, Alexei A.;Brown, R. Stan
通讯作者：
Brown, R. Stan
影响因子：
15
作者：
Linjalahti, Heidi;Feng, Guoqiang;Williams, Nicholas H.
通讯作者：
Williams, Nicholas H.